Unexpected catalysis: aprotic pyridinium ions as active and recyclable Brønsted acid catalysts in protic media
作者:Barbara Procuranti、Stephen J. Connon
DOI:10.1021/ol802008m
日期:2008.11.6
Simple pyridinium salt derivatives have been (rather unexpectedly) shown to promote highly efficient acetalization reactions of both aldehydes and ketones at ambient temperature. The optimum catalyst is aprotic, yet it can promote the formation of benzaldehydedimethylacetal at 0.1 mol % loading more efficiently than a protic Bronsted acid catalyst with a pKa of 2.2. The process is of wide scope with